fun main() {
// val s1=Students("张三", 18, "1班", 90)
// val s2=Students("张三", 18, "1班", 90)
// println(s1==s2)
// s2.grades=80
// println(s1==s2)
// var (name,age)=s1
// println("$name,$age")
SettingManager.toggleDarkMode()
SettingManager.toggleDarkMode()
SettingManager.toggleDarkMode()
}
// data class Students(
//     val name: String, 
//     val age: Int,
//     var className: String,
//     var grades: Int
//     )
object SettingManager{
    var darkMode: Boolean = false
    fun toggleDarkMode(){
        darkMode=!darkMode
    println("Dark mode is now ${if (darkMode) "enabled" else "disabled"}")
    }
}